Extruding apparatus



K. B KILBORN EXTRUDING APPARATUS July 6, 1948.

Filed June 19, 1944 4 Sheets-Sheet 1 y vK. B. KILBORN 2,444,831

EXTRUDING APPARATUS I Filed June 19, 1944 v 4 Sheets-Shet 2 July 6,1948.

K. B. KILBORN EXTRUDING APPARATUS 4 Sheets-Sheet 3 Filed June 19, 1944Patented July 6 1948 Karl B' ki lborn Akron, Ohio; assi'glu'ir to-wing-' foot Corporation,- Akron, Ohio, a corporation of DelawareApplication 19, 1944', Serial N6. 540,953

This invention relates to machines for ex: truding plastic materialcommonly knownas tube-machines or pressure machines; More particularlythis'inv'ention relates to an apparatus including a pair of tubemachine's' i-or extruding uncured rubber compound in" plastic formthrough a die head and die for forming strips of material of suitableshape and width to form composite strips for the outer wearing'surfaceof vehicle tires such as the tread and sidewalls thereof. v

, Strips of this character are necessarily of dif ferent thickness andwidth according to the size of tire onwh-ic'h they are to be used, anduniform density is hard to control without the properpredeterminedrelationship between the volume of stock to the size of the die.

In previous apparatus of this character,'a pair of tube machines inopposed relationship ex'tru'de plastic material through a common diehead pro"-' vided with a pair of cavitiesone of which conducts plasticstrip-material suitable'for the tread or ground contacting portion andthe other cavity conducts strip material suitable" for forming: sidewallportions of a tire, both strips converg mg at a common die andunitingto-foi'm unitary strips suitabl for forming the entire'outer'cov' er'ing'of a tire carcass. Previous apparatuses of thischaracter are provided with a die h ead com= prising a mainbody and acapbolted thereto, Said cap being" removable for ins ection and cleaningof the cavities; but the objection found in its construction isthat partof the cavities are formed in the-cap and part in them'ain bodyjofthe'die head, which're'quires removal of themtii'e die head and theSubstitution Of another one when it is desired'tochange from one sizedie head to another. This is a very heavy'and laborious'task, for whensuch a change is made; it is necessary to move one-oi the tubemachinesaxially in order to provide'the proper clearance for removal of the diehead. "Thisfresults' a substantial loss in production as wen as tiineand labor, and an unnecessary use of materialand the costly machine workthat accompanies the production of a die head' of this character.

In some instances, in order to avoid changing the die head'f'ordifierent size of composite strip,

a diehead having larger cavities than is required foracertain" size ofstrip is used. For example, if a die head having a 'cavity'36 incheswide were used to form a strip 24 inches wide, a G'i'nch dead spot wouldbe created on. either s'i'de where the plastic stock would not move; Dueto'the heat ofthe" the head this dead stock would" slowly" viiicanize,causing a bad. condition and a waste of material; This condition waspartially relieved by 'irovidi'ng orifices at the sides of thec'aviti'es' to permit the excess stock to bleed off. This ex cessmaterial was their returnedto a mill to be reworked. At best this methodwas inefilcieht and resultedin a waste or time, labor and material.Obviously, by thus bleeding "off the ex"- cess stock, uni-formity indensitywas more difii= cult to control and reflected adversely in thecost and quality of the completed strips.

Ah object of this invention is to eliminate the foregoing objectionstoprevious apparatus to which this invention relates, by providing a pleadie head comprising a fixed main" master body in which a chamber isformed the inner wall's'or faces of which possess plane smooth stirfacesvoid of cavities to receive cavity'blockspro= vided with total cavitiesin their faces whereby said cavity blocks cooperate with the plane facesin said chamber in sealing and interchangeablerelationship. The chamberinthe fixed main body of the die head is designed to receive int-erchangeable blocks containing total cavities of various forms so thatcavities of theprop'er proportions and relationship to'the" size ofdie-may be readily available Without disturbing the mainmasterbodynfthe'die' head.

' other object of the invention is to provide a die head wherein theplastic conducting cavities therein will always be of a formwhereby'th'e volume of the plastic material will be in properrelationship to the size of'th-e diebeing used and withthe assurancethat the 'composites'trip will be of uniform dehsityand of the roperdiniere sites.

"Anotherjotiject of this invention is to provide a swingable pneumaticmeans to-holdthe die block in place. Obviously; each size of compositestrip requires a corresponding size of die-and when the cavity block orV-block is changed, it is necessary toalso-remove the die block to whichis attached a die of the proper dimensions: The the blocks are easilyand quickly released or clamped in place by the manipulation of a valveto direct air under pressure from one end-of air cylinders to the other.This avoids the necessity of removing nuts, bolts or wedges that wereformerly used to secure the die block to the; die haid'. f

Thus; it WilTbe apparent thatproviding a'die headwherein the magi bodythereof become a permanent fiiit'ure'in an apparatusof this charac'tei', arid whereby only the cavity block or V lilock need"bereplace'cl for different sizes; and

the simple and expeditious pneumatic clamping arrangement to hold thedie block in place, will save time and labor and the eficiency of theapparatus will be substantially increased.

The objects and advantages of this invention will be more fullyunderstood when considered in connection with the following detaileddescription and thesaccompanying drawingsin which: Figure *1 is a sideelevation ;of 'thejapparatusf, Figure 2 is a fragmentary cross-sectionalview of the die head;

Figure 3 is a side view of the die head;

Figure 4 is an nd view of the die hea'd passes through the die, as shownin Figure 8.

Figure 5 is a semidiagrammaticibottom view-.,

of the cavity block or V-block, withdifierent sizes of cavities shown indotted lines;

Figure 6 is a sectional view taken on the line a 6-6 of Figure 2 throughthe tread cavityf Figure '7 is a sectional view taken ontheline,

1-! through the under-tread and sidewall cavd' 1 i :I

, Figure 8 is a View of the die plate showing the ilnaliorm oftheplastic as it passes therethrough. I v a V Referringto the drawings,the. apparatus com-.- prises bases l and} on which ,aremountedrespectively a pair t conventional tube=machines 3 and,4 providedwith conveyor, screwsj and 6 rotatably mounted in cylinders Land 8.

The cylinders 1 and-8 are provid d. with hoppers 9 and ID into which arefed strips of plastic material ii andl2, each strip being of a differentcompound. Obviously, ifdesired the strips ii, and 12 may be ofthe'samecompoundf.

It wilhbe noted that the tubemachines 3 and-4 are of different sizesandcapacitiesd For the par-1 pose of illustration the respective sizes01 12 inch and Binch mesh are herein shown and described, but machinesof equal size or any available com: bination of sizes may be used,depending upon the size and capacityurequired for forming the variousstrips that; converge to form acomposite strip, aswill be describedlaten 3 The tube machines 3 and 4 repositioned in axial alignment infaceto face or opposedrelationship, and have-mounted therebetween a diehead, indicated generally by the numeral l3 in axial alignment with saidtube machines, g 1 .The. die head comprises .a main fix ed master body14 provided with flanges l and 16' which coincide with flanges i1 and 18respectively of the. tube machines 3, and 4 and ar e attached theretothrqughthe medium of stud, bolts I9. The mainbody of the die ahead l4has formed therein a chamber 2!, the angular sides ,ofwhich are in thegeneral form of the letter V when viewed, transversely with respecttothe axis of the tube machine, the angular sides being defined bythelines ,22, 23, 24-and 2 5- (see Figure 2) .These chamber wallsareprovidedwith'plane smooth suriacesvoid of depressions. [The portion ofthe chamber closely adjacent the tube machine orifices is shaped toconforni thereto. The ends ofsaid chamber are terminated by plane smoothvertical walls 26. ,1 Formed toiit in-tinterchangeable and sealingrelationship in, said chamber 2i, cavity blocks or V-biocks 21 withangularjsides .or -facesfwhich coincide with the plane walls .22, 23,'Hand 25 of the chamber have passageways or' cavities I28 and 29formedtherein. The cavity 28, conducts the plastic material whichformsthe 'underti'ead and sidewall portions, oi 'a composite strip f'andthe cavity 29 conne'sts the 'plasti m'aterial for the tread portion,,both cavitiesconvergingat a From the die the composite strip isdelivered vertically downward onto a conveyor belt 33 and is conveyedthrough a cooling tank in the usual course. of preparing strips of thischaracter.

The V-block TI-is provided with flanges and t firmly attached, to thedie head by the stud 'b'olts'34 and'nu ts 35 and both the block and headare provided with chambers through which fluid is circulated in ordertomaintain the proper temperature of the plastic stools, while passingthroughthe passages provided therefor.

In the bottom of the die head l3 a recess ,or groove 3- 6.is formedtoreceive the upper portion 31 of a die block 31. SaiduDper portion isprovided with a slot into which is fitted a die plate 39 whichis clampedinto placeby a lower portion 40. of the die block 3 I. Said upper andlower portions of the. die block are held in alignment through the aidof keys 4|.

In order to lock the die block 3! in the recess 36, the lower portion 40has extending therefrom on either side and for the entire length of said die. block, angular surfaces 42, for the purpose of cooperating withlooking bars 4? formed on the ends, of arms 44 pivotally mounted onshafts 45 which in turn are su pportedby. bearing arms 46 and 41extending from the die head 13. The locking bars are actuated :by pistonrods 48 piv; otally attached to thearms 44, as at. 49 Said piston, rodsare actuated by pistons 50 operating within cylinders 5| whicharepivotally mounted on projections ;52 and .53 extending from the mainbody of the master die'head 14 by pivot pins 54. When air under pressureis admittedto the pivoted end 015 the cylinders through the ports 55 thepistons operate toswingthe arms 44 in alocking osition, as indicated inFigures land 3, and when air under pressure is admitted; through the-portsfiii, the arms 44 will 3 swing clear or the die block 3], asindicated in dotted linesin Figure 3 of the drawings, to permit the. m ao the ie'mock assembly, g a

It will behoted that the die block. 31 is provided with an opening 51inits upper sid'a Said opening coincides with the cavities R -and .29 andalso with the/opening in thedie plate 39, in order to produce acomposite strip that will be or uniiorrn dimensions and density it isobvious that thecavities orpassageway sin the V -blocks andthe die blockand die must be of a proper predetermined relationship in order toobtain sa s ac or u i m t and r- Althou h the invention is shownanddescribed, as appli cable to a .dual assembly of tube machinesrequiring a" duplex die headthe invention is also applicable to'singletube machines by providing a fixed master head capableoireceivinginterchangeable cavity blocks in which one or more cavities maybe formed to. convey plastic mate rial from an extrudingmachine toadie'to form plastic. strips.

From the foregoingdescription it apparent that thdpiactice of, thisinvention will:

prev ew s stanti ailin in. ime like? n material and will provide a moreuniform product, all of which will be reflected in improved quality andlower cost of the finished product in which unitary strips of thecharacter disclosed become a part. Various forms and numbers of stripsmay be formed in accordance with the teachings of this invention, and itWill be understood that the invention be limited only by the scope ofthe appended claims.

I claim:

1. An extrusion means for forming a composite strip of plastic materialembodying portions having diiferent physical characteristics, saidextrusion means comprising a main body member having a generallyV-shaped chamber therein delined by plane wall surfaces extending froman Opening p ng the V to an opening at the apex thereof; shaping meanson the main body member adjacent the apex opening; a removable generallywedge-shaped cavity block, the inclined walls of which contact the planewall surfaces of the chamber; and a plurality of grooves formed in theinclined walls of the cavity block cooperating with the plane wallsurfaces of the main body member to define a series of individualpassageways leading to the apex opening in the chamber.

2. An extrusion means for forming a composite strip of plastic materialembodying portions having dilferent physical characteristics, saidextrusion means comprising a main body member having a chamber thereinopen at one end thereof and of substantially V-shaped cross-section inone of its dimensions, said chamber being defined by plane wall surfacesconverging toward an opening at the apex of the chamber; shaping meanssupported by the main body member adjacent the opening; a removablecavity block having two inclined walls which define a wedge-like shape,said inclined walls :having formed therein a plurality of grooves ofgenerally curvilinear cross-section, the marginal portions of whichcontact with the plane wall surfaces of the chamber when the cavityblock and the main body member are interfitted to form in cooperationwith said plane wall surfaces a number of passageways all of whichconnect with the opening in the chamber; and releasable locking meansfor demountably supporting the shaping means on the main body member.

3. A die head for forming and uniting strips of plastic material havingdifferent characteristics comprising a permanently fixed master bodyhaving a chamber therein, said chamber being defined by plane surfaces;a cavity block supported in said chamber provided with oppositelydisposed converging Walls the marginal portions of which rest upon saidplane surfaces in said chamber in sealing relationship; a groove in saidmaster body; a divided die block positioned in said groove having aforming die positioned therebetween; passageways formed in theconverging walls of the cavity block to convey strips of plasticmaterial therethrough to the forming die, said forming die having asingle opening therein; angular surfaces formed on said die block; andmeans for locking said die block in said groove embodying pivotallymounted locking bars, piston rods pivotally connected to said lockingbars, and air cylinders for actuating the piston rods, whereby saidlocking bars are brought into contact with the angular surfaces on saiddie block to lock said die block in said groove.

KARL B. KILBORN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,422,356 Heller July 11, 19221,952,469 Snyder et al Mar. 27, 1934 2,061,407 Royle Nov. 17, 19362,096,362 Lehman Oct. 19, 1937

